1. Field of the Invention
The invention relates generally to underwater salvage lift systems, and more particularly to such system employing controlled buoyancy devices and a tether system having brake mechanisms.
2. Description of the Prior Art
Many devices have been utilized by divers to salvage objects from the ocean bottom. These range from plastic bags to inverted buckets that generally have been inflated or buoyed up by filling the device with scuba air from breathing gas bottles. No control was provided.
Recently, rigid devices have been provided having zipper closures which can be used to regulate lift capability by allowing excess gas to spill at any setting of the zipper slide. Some of these rigid devices have been provided with self-contained air supplies, generally limited. However, these rigid body devices are large and bulky, hence, difficult to handle by divers. Also, they have no means by which their rate of ascent can be controlled. As a result, injuries to surface objects and personnel often occur.